The invention concerns a steam and condensate coupling for a drying cylinder in a paper machine.
By means of a steam and condensate coupling for a drying cylinder, a pressure-tight joint is formed between the revolving axle of the drying cylinder and the stationary constructions. By means of spring force and steam pressure, a seal ring is present against a revolving flange attached to the end of the axle. Steam and condensation pipes are passed through the axle journal, and a seal ring is fitted to surround said pipe systems.
The installation of a prior art coupling is a time consuming operation that imposes high requirements. The flanges attached to the end of the axle of the drying cylinder performs a swinging movement axially and radially. Frequently, such swinging remains to be corrected after the installation. Another drawback is that the replacement of the carbon seal in the coupling constructions is difficult to carry out. Also, the force with which the carbon is pressed against the flange attached to the end of the axle depends on the spring forces of the springs and of the bellows. Thus, the adjustability of the force is poor and, when the carbon seal is worn, the spring force becomes lower.
In the prior art coupling constructions, in starting situations, a high starting friction is produced on the carbon seal. Thereby the carbon is worn and damaged rapidly.